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6-Contributor
Feb 28, 2026 4:14 PM UTC
Solved

Plot variables over a common X-Axis

Hi PTC Community -

 

I have two variable quantities (Water & Ammonia) evaluated over two different temperature ranges over which only they are each valid.

I would like to plot both with a common x-axis range (-70°C to +370°C), and not be limited to either the T1 or T2 (MIN, MAX) range.

See how the Ammonia (pink) plot is being limited to the MIN(T1) value of 1°C.

 

See attached. I am using Mathcad Prime 11.0.1.0.

 

Your tips and suggestions for a fix will be appreciated.

 

Regards,

thodij

Werner_E
Werner_EAnswer
25-Diamond I
Feb 28, 2026 6:41 PM UTC

Like this?

grafik.png

You can add expressions at the abscissa the same way as you did at the ordinate - either via the menu using "add trace" or by the keyboard short Ctrl+Enter

5 replies

23-Emerald V
Feb 28, 2026 4:37 PM UTC

Add a second ordinate expression, match the order up such that you have the right T(2?) to go with the ammonia and then T(1?) with water.

 

Success!
Luc

 
 

 

 

 

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thodij6-ContributorAuthor
6-Contributor
Feb 28, 2026 4:50 PM UTC

Luc,

 

Thank you for your response.

I do not see how to do that from the plots menu.

 

Thanks,

thodij

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23-Emerald V
Feb 28, 2026 6:44 PM UTC

Put your cursor on the T1 (X-axis variable) and select "Add trace" from the Plots menu.

Now the order of X-axis expressions must match what is needed for the corresponding Y-axis expression.  If there are less X-axis expressions then Y-axis expressions, the last X-axis expression is used for every subsequent Y-axis expression. That is what you had (1 X-axis expression for the first, and the second Y-axis expression).
In the mean time, Werner has shown what it looks like.

 

It's as simple, and intuitive as every other interface of Prime.

 

Success!
Luc

 

 

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Werner_E
Werner_E25-Diamond IAnswer
25-Diamond I
Feb 28, 2026 6:41 PM UTC

Like this?

grafik.png

You can add expressions at the abscissa the same way as you did at the ordinate - either via the menu using "add trace" or by the keyboard short Ctrl+Enter

Translate
thodij6-ContributorAuthor
6-Contributor
Feb 28, 2026 7:42 PM UTC

Perfect!

 

This is what I am looking for.

 

Thanks to Werner, and Luc.

 

Regards,

thodij

 

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